From Dr. David Marlin
HORSES, HEAT, SWEATING, COLD-WATER, COOLING, SCRAPING
At the risk of preaching to the converted, as a few people are still sending me articles, often written by lay people, sometimes from vets, and telling me how wrong I am, I thought I’d try a pictorial approach 🙂
Per litre, Ice-Cold water (0-5°C) removes heat faster than evaporation of 1 litre of water or sweat.
Per litre, the complete evaporation of 1 litre of sweat or water removes 13x more heat than 1 litre of ice-water BUT evaporation takes 10-15x longer to remove the heat.
COLD WATER = QUICK COOLING, BUT WASTEFUL OF WATER (INEFFICIENT) – USE FOR RAPID COOLING
EVAPORATION OF WATER OR SWEAT = SLOW, BUT DOESNT WASTE WATER (EFFICIENT) – USE FOR KEEPING HORSES COOL
MYTHS
Myth 1 – “You should never put cold water on a hot horse”
Explanation – Ice-cold water(0-5°C) on hot horses does not cause shock, laminitis, kidney damage, muscle damage, tying-up or heart attacks!
Myth 2 – “Water left on a horse will heat up and insulate and make the horse hotter.”
Explanation – Flawed physics! Water is a better conductor of heat than air. A wet horse will actually cool faster than a dry one, even if humidity is 100%.
Myth 3 – “Scraping is essential.” Explanation – Scraping just wastes time that could be better used putting more water on to cool by conduction. Scraping also wastes water when water is in short supply. Water which could evaporate on the horse. Water evaporating on the ground doesn’t cool horses down.
Myth 4 “Concentrate on large veins, arteries inside the back legs, large muscle groups”
Explanation – NO. Cooling by evaporation or conduction works by cooling the blood flowing through the small blood vessels in the skin. The more skin you cool, the quicker you cool the horse. Apply water all over.
How do I know all this? 25 years working on equine thermoregulation. 20 plus scientific papers on equine thermoregulation. Working with endurance horses in the Gulf. Advising the racing industry on prevention and management of heat-stroke. Working with Governments on heat legislation. Working with charities on thermal stress. Working on the 1996 Atlanta, 2004 Athens, 2008 Beijing Olympic Games. Currently working on the 2018 Tryon World Equestrian Games and Tokyo 2020 Olympics. Author of the FEI Guidelines for National Federations on the management of horses in thermally challenging conditions. https://inside.fei.org/sites/default/files/Session_6_Optimising_performance_in_a_challenging_climate_SUPPORTING_DOC.pdf
For USPA Open type high goal matches, with each player bringing between 10-14 horses per game, there are on average 100 horses participating in each match. The picture below shows a “palenque” or pony line where the horses stand waiting to be tacked up and play. Polo ponies are exercised together and are accustomed to being in close proximity to other horses.
